Transposable Elements (TEs) were discovered by Barbara McClintock, for which she earned a Nobel Prize in 1983.
They are DNA sub-sequences that can move around the genome + are otherwise known as transposons. TEs come in two flavours: retrotransposons (Class I) + DNA transposons (Class II).
Use a 'copy + paste' mechanism, known as conservative replication or replicative transposition, thereby extending the genome.
The mechanism involves an RNA intermediate + reverse transcriptase.
Is comprised of five orders
Long Terminal Repeats (LTRs)
Dictyostelium Intermediate Repeat Sequence (DIRS)
Penelope-Like Elements (PLEs)
Long Interspersed Nuclear Elements (LINEs)
Short Interspersed Nuclear Elements (SINEs)
Use a 'cut + paste' mechanism, known as non-conservative replication or non-replicative transposition, which does not result in extension of the genome.
Comprise < 2% of the human genome
There is no RNA intermediate involved.
Encode the enzyme transposase, to facilitate the integration of the excised DNA back into the genome.
is comprised of two sub-classes
Orders and superfamilies of TEs are largely based on Target Site Duplication (TSD) lengths. TSDs are sequences that flank insertions of TEs + are commonly shorter than 10bp.
Why do we care about TEs? Here is one reason: more of them are found in cancer cells than normal cells. 
2. https://en.wikipedia.org/wiki/Transposable_element [image]
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